feat(enrichment): Typosquat & dependency-confusion detector

[JSONbored]

Context

A REES (review-enrichment service) analyzer. Tier: high-value.

Detects: A newly-added dep whose name is a near-miss of a popular package (edit-distance/homoglyph/scope-swap) OR an internal-looking unscoped name that is publicly claimable (namespace-takeover risk).

Data source: Bundled top-N popular-package list per ecosystem for the Damerau-Levenshtein/homoglyph compare; npm/PyPI registry 404 + scope-existence check for confusion; deps.dev for popularity rank. Free.

This is heavy/external/historical analysis the no-checkout headless claude --print reviewer cannot do; the REES returns it as a brief block the engine splices into the review (additive + fail-safe).

Implementation (established pattern, all inside review-enrichment/)

1. Finding type + BriefFindings key in src/types.ts
2. src/analyzers/<name>.ts — pure, inject fetch for tests
3. Register in src/brief.ts ANALYZERS registry
4. Render a public-safe block in src/render.ts
5. node:test units against dist/ + a live smoke against the real data source

Deliverables

• The analyzer + wiring + tests + a verifiable brief block (file:line or package@version)
• Clean PR off main (zero engine conflict; outside the engine tsc/vitest/codecov scope)

Parent: #1499